Batting trainer apparatus and method



United States Patent Inventors Appl. No.

Filed Patented Assignee Max E. Hill St. Paul;

Dean A. Fjeldstad, Minneapolis; Jerome E. Schrnitt, Northlleld, Minnesota 757,300

Sept. 4, 1968 Dec. 8, 1970 Killebrew Inc.

Salt Lake City, Utah in corporation of Utah. by mesne assignments BATTING TRAINER APPARATUS AND METHOD 15 Claims, 12 Drawing Figs.

Int. Cl.

References Cited UNITED STATES PATENTS 2.664.077 12/1953 Moore A63b 69/40 Field of Search 273/26, 69; 124/16, 37, 38

3,138,381 6/1964 .Branneman 273/26 3,246,895 4/1966 'Traill; 273/69 3,368,541 2/1968 Brink 273/26 Primary Examiner-Richard C. Pinkham Assistant ExaminerTheatrige Brown Attorney-Lynn G. Foster ABSTRACT: A batting trainer apparatus and method, the apparatus including a ball-holding pedestal and an associated compression spring interposed between the pedestal and a spring retainer, the position of the retainer being vertically adustable to selectively regulate the force exerted by the compressed spring against the pedestal and therefore the height to which the ball is thrown when the spring force is released. A

vertically disposed latch rod has a leading end integral with the pedestal and a trailing end comprising a reduced diameter portion adapted to be received and temporarily locked in position when the pedestal is displaced downwardly and the spring is compressed. The latch rod is liberated from the locked position when a foot-operated treadle is first depressed into cocked condition and thereafter released.

PATENTEI] BED 8mm SHEET 2 BF 2 mvsmons. MAX mu. DEAN FJELDSTAD JEROME SCHMI ATTORNEY baseball bat is of key importance in successful batting.

Although ball throwing devices are numerous in the art (see, for example, U.S. Pat. Nos. 2,705,003 and 3,368,54l) a simple, reliable plunger apparatus accommodating essentially vertical projection of the ball to any selected one of several possible heights, which projection is initiated by movement of a foot during the stride, has not, until this present invention, been disclosed or suggested in the art.

It is therefore a primary object of the present invention to provide a novel batting trainer apparatus and method accommodating improved baseball batting practice and training.

It is another important object of the present invention to provide an improved apparatus and method which cause a ball to be thrown essentially vertically in the air to a height within the strike zone of a player.

Another and no less important object of the present invention is to provide a novel training apparatus triggered by the natural striding movement of a foot.

One still further object of the present invention is to provide a novel apparatus which is adjustable to selectively throw a ball to any one of several possible predetermined heights.

These and other objects and features of the present invention will become more fully apparent from the following description and appended claims taken in conjunction with the accompanying drawings wherein:

FIG. I is a fragmentary longitudinal cross section in vertical elevation of the presently preferred embodiment of this invention illustrating the ball throwing portion in the at rest extended condition; 1

FIG. 2 is a schematic perspective of the ball throwing portion of the apparatus of FIG. 1;

FIG. 3 is a transverse cross section taken along lines 3-3 of FIG. 1;

FIG. 4 is a fragmentary cross section of the lower portion of the ball throwing device of FIG. 1;

FIG. 5 is a cross section taken along lines 5-5 of FIG. 4;

FIG. 6 is a schematic perspective illustrating the operation of the latching structure of FIG. 5;

FIG. 7 is an enlarged fragmentary elevational view of the attachment of the movable foot treadle to-the base of the device;

FIG. 8 is a schematic perspective of the presently preferred embodiment of the invention illustrating the preferred method of use;

FIG. 9 is a fragmentary perspective of a portion of the latching mechanism of FIGS. 5- and 6; and

FIGS. 10 through 12 fragmentarily illustrate in elevation the operation of unlatching the latching mechanism of FIG. 9.

With specific reference to FIG. 1, a ball projecting mechanism, generally designated 20, is fixed in the erect illustrated position upon a base member 22 by screws 21 or the like (FIG. 3). The ball projecting mechanism (FIGS. 1-4) principally comprises a ball-holding device or pedestal 30, which is generally cup-shaped and adapted to support a baseball 32 or the like (FIG. I The lower base portion 34 of the pedestal 30 is provided with a concentric aperture 36 which the threaded end '38 of a generally vertically disposed latch rod or plunger 40 loosely passes. The latch rod 40 is retained in the mentioned position by spaced nuts 42 and 46. Lockwashers or the like may also be used.

A pair of upper contiguous retaining plates 44 is interposed between the bottom surface of the base portion 34 of the pedestal 30 and the nut 46 threaded on the latch rod or plunger 40. The bottom surface of the lower retaining plate 44 provides a bearing face for the upper end 48' of a vertically disposed helical compression spring 50. The lower portion 52 of the spring 50 bears upon the top surface of a lower spring retaining plate 54 (FIG. 3). The upper retaining plates 44 are reciprocably movable with the spring 50 axially within the cylinder 64, which will be subsequently more fully described. The retaining plates 44 have an outside diametrical dimension slightly smaller than the inside diametrical dimension of the cylinder 64 to allow for relative movement. Thus, the plates 44 and the cylinder 64 help guide the plunger 40 and the pedestal 30 along a vertical path when the plunger 40 and spring 50 are displaced from the position of FIG. 1 to the loaded position of FIG. 4. Conversely, when the plunger 40 and spring 50 are released from the loaded position and move to the position of FIG. 1 to toss the ball, the plates 44 and cylinder 64 help guide the pedestal 30, plunger 40 in a vertical direction so that the trajectory of the ball is vertical within the strike zone of the batter.

The lower retaining plate 54 is provided with radially projecting wing portions 56 and 58 (FIG. 3) adapted to project outwardly through slots or keyways 60 and 62, respectively, in a vertically extending cylinder or casing 64. The cylinder 64 concentrically surrounds both the spring 50 and the latch rod or plunger 40. The cylinder 64 is provided at its upper edge 66 with an inwardly directed shoulder or lip 68 which cooperates with the top surface of the top plate 44 to provide a stop, limiting the extended position of the plunger 40 and the spring 50. The lower portion 70 of the cylinder 64 is concentric within and integrally attached (as by welding brazing or the like) to the inside cylindrical face of an externally threaded sleeve 72 (see FIG. 4), which sleeve may be considered part of the cylinder, and is integrally attached in butt relation (as by welding, brazing or the like) to a generally circular laterally disposed support plate or platform 74 which presents a central aperture 79 of diameter equal to the inside diameter of the threaded sleeve 72.

Structure is provided for selectively setting the force to be exerted by spring 50 in throwing a ball into the air. More specifically, an outer adjustable collar 76 (FIGS. 1, 2 and 4) has a stepped bore, the lower, smaller diameter portion of which is internally threaded at 77 and threadedly engages the external threads of sleeve 72, the upper surface 75 of the collar 76 bearing against the lower surface of the radially disposed wings 56 and 58 of the lower spring retaining plate 54. When the spring force adjusting collar 76 is rotated to advance the collar upward on and relative to the threaded sleeve 72, the radially projecting wing portions 56 and 58 will be upwardly advanced along paths defined by the keyways 60 and 62 thereby compressing the spring 50 by reason of its bearing relation against plate 54. This preloads spring 50 to a greater degree and will cause the spring to hurl the ball a greater distance into the air when released from a loaded or cocked position.

With continued reference to FIGS. 1 and 4, the lower or trailing end 80 of the latch rod 40, is disposed in slidable relation within a cylindrically-shaped hollow guide 82 disposed essentially concentric within the cylinder 64. The guide 82 has an inside diameter which is slightly greater than the outside diameter aligned the latch rod 40, the guide 82 cooperating with the retaining plates 44 to cause the plunger 40 and pedestal 30 to at all times move in a vertical path between the loaded and the released positions. The lower end of the guide 82 terminates in an essentially circular laterally projecting flange 84, having a central opening which receives the tubular guide 82, the assembly being secured in the described and illustrated relation by welding, brazing or the like. The flange 84 is provided with peripherally spaced apertures 86 disposed in alignment with apertures 88 in the support 74. The aligned pairs of apertures are adapted to receive screws 21 (FIG. 4) or, alternatively, bolts or the like for attaching the ball projecting element 20 to the base member 22.

The latch rod or plunger 40 is further provided with a tapered surface 43, a reduced diametered portion 37 and a spearhead 41 (FIGS. 2 and 4) seriatim below the trailing end thereof. The spearhead 41 present an upwardly facing abutment surface or shoulder 39 and a downwardly pointed surface 47.

The base member 22 (FIGS. 4 and 5), to which the mechanism is attached, comprises a recess 92 located adjacent the base of guide 82. The recess 92 is above a vertically disposed aperture 94 in the base 22, the aperture 94 being axially aligned with the bore of guide 82 and with the latch rod 40. The aperture 92 adapted to receive the tapered tail portion 41 of the latch rod 40 against the bias of the spring 50 when the latch rod 40 is fully depressed into its latched, cocked or loaded position, hereinafter to be more fully described. The recess 92 contains plunger latching structure including movable detent or plunger latching plate 96 (FIG. 6), the latching plate 96 being centrally elevated or upwardly offset between shoulders 98 and 100 and lower flat edges 101 and 103 (FIGS. 4 and 5). The plate 96 is centrally provided with an aperture 122 which is preferably napiform, teardrop or pear-shaped in configuration.

The plate 96 is pivotally attached to the base member 22 at lower flat edge 101 by means of a screw 102 (FIGS. 5 and 6), the screw 102 acting as a pivot point to accommodate rotational displacement of the plate arcuately around the screw 102 relative to the base. The plate 96 is pivotally attached to an elongated arm or actuator bar 104 at lower flat edge 103 by a pivotal connection or pin 106. As best illustrated in FIGS. 1 and 9, the actuator bar 104 is provided at its trailing end with an offset end 109 thereby providing an upstanding shoulder 108 adjacent the end 109 (FIGS. 1 and 9). The trailing end 109 and the shoulder 108 of the displace bar 104 are also provided with a longitudinal slot 110, best illustrated in FIG. 9. The longitudinal slot 110 receives a rigid vertically extending plate 112which presents a sloped ramp surface 113, accommodating a releasable association between the bar 104 and the treadle 24 in a manner which will hereinafter more fully be hereinafter more fully described. The plate 112 is integral with base 115 which is screw secured to the underside of the base 22 see FIG. 1).

As illustrated in FIG. 1, the actuating bar 104 is attached along its underside at 114 to one end of tension spring 116. The spring 116 is disposed in a longitudinal recess 118 in the base member 22. The opposite end of the spring 116 is attached at 120 to a vertical wall of the recess 118 and biases the bar 104 and the pivotally attached plate 96 to the latching position whereby the tapered edged 123 of the teardrop aperture 122 are partly superimposed over the aperture 94 and partly cover the bore of guide tube 82 as illustrated in FIGS. 5 and 6. The aperture 122 is adapted to receive and hold the spearhead 41 of the latch rod 40 in the cocked, loaded" or latched" position. More particularly, when the latch rod 40 is manually depressed by the user counter to the bias of spring 50, the pointed surface 47 of the spearhead 41 will strike the tapered edges 123 of teardrop aperture 122, forcing the plate 96 and the bar 104 to an open position toward the right as viewed in the FIGS., counter to the force of spring 116. This allows the spearhead to pass through the aperture 122 following which the force of spring 116 returns bar 104 and plate 96 nearly to the initial position. Thus, the tapered edges 123 of aperture 122 become contiguous with reduced diameter portion 37 of shaft 40 and the plate 96 will be superimposed over and tightly engage the shoulder 39 of the spearhead 41 by reason of the force of spring 50 and the plunger 40, the pedestal 30 and the ball 32 will be restrained in the loaded position. The mentioned displacements of the bar 104 into the loaded position is accommodated by the treadle 24 and associated pawl 126 when in the illustrated elevated position of FIG. 1.

The treadle 24 is preferably exteriorly coated with a nonslip abrasive material and is supported above a relatively large longitudinal slot 128 in the base member 22 by essentially U- shaped brackets 130 and 132 (see FIGS. 1 and 7). The brackets 130 and 132 are essentially identical. The ends of each bracket 130 and 132 are pivotally mounted in correspondingly sized holes in the base member 22 and rest upon and are held in the holes by transverse plates 134 and 136, respectively. The plates 134 and 136 are fastened at their ends to the base 22 by screws 137 or the like. The upper portions 142 and 144 of the essentially U-shaped brackets 130 and 132 respectively are pivotally attached to the treadle 24 by means of rivet secured anchors 138 and 140. Thus, the treadle 24 is capable of a to-and-fro rocket" motion.

A tension spring 156 (FIG. 1) is disposed within the base slot 128 and is connected at the leading end 158 to the treadle 24 and at the trailing end 160 to a transverse plate 162 which is screw secured to the base member 22 and bridges the longitudinal slot 128. The spring member 156 urges the treadle 24 toward the right, away from the ball-projecting element 20 in a path defined by the rocker motion of the brackets and 132. The mentioned rightward movement is limited by stop" engagement between downwardly extending end 149 of the treadle and vertical wall 151 of the slot 128 in the base 22. This position is illustrated in FIG. 1.

The treadle 24 is rivet connected to a vertically displaceable, resilient arm 162 which terminates at the left in a downwardly directed pawl 126. In the at rest condition, the pawl 126 is urged by spring 156 against the sloped surface on ramp 113 of the plate 112 at a location directly above the offset end 109 of the bar 104.

In the operation of the illustrated embodiment of the invention, particular reference is now made to FIGS. 8 and 10 12. Initially, with the collar 76 and the ears 54 and 56 correctly set in relation to the remainder of mechanism 20 to insure that the ball 32 will be vertically tossed to a suitable height, the pedestal 30 and attached latch rod or plunger 40 are vertically displaced downward until the latch rod passes through the aperture 122 in the plate 96. The vertical displacement may take place with the ball 32 in position on the pedestal 30, or the ball 32 may be placed on the pedestal after the displacement step. When the plate 96 moves by action of the spring 116 into the annular recess 37, in the latch rod 40, the plunger 40 is latched against the shoulder 39 of spearhead 41 (see FIG. 6) and the spring 50 is retained in a highly compressed condition. When the spring is retained in the compressed condition and when the ball 32 has been located properly on the pedestal 30, the ball-projecting element 20 is in a loaded" or cocked" condition as illustrated in FIGS. 4, 6 and 8. Thereafter, the person using the device will place his forward foot and part of his weight on the treadle 24. This will depress the treadle 24 toward the left causing the lip 149 to disengage the wall 151 and the treadle to rock toward the left from the position of FIGS. 1 and 10 to the position of FIG. 11. The abrasive exterior surface of the treadle 24 will prevent inadvertent slipping of the foot relative to the treadle. Thus, depression of the treadle 24 will cause the pawl 126 to move leftward and downward over the shoulder 108 of the bar 104. At this point in time both the treadle 24 and the ball-tossing mechanism 20 are in their respective cocked" conditions.

When the user of the device thereafter removes his foot from the treadle as he strides forward with his leading foot, i.e. from the solid line to the dotted line position of FIG. 8, the pawl 126 will retract to the right due to the memory of spring 156 thereby causing the shoulder 108 and the attached bar 104 to also be pulled to the right as they follow the movement of the treadle. The ramp 113 will cause the pawl 126 to be gradually lifted upwardly as the treadle moves to the right. Lateral displacement of the displace bar 104 will cause the plate 96 to rotate clockwise as viewed in FIGS. 5 and 6 until the shoulder 39 no longer is engaged by the plate 96, which releases the latch rod or plunger 40. This happens at a point in time when the relation between the pawl 126 and the shoulder 108 is about as illustrated in FIG. 12. Instantly, the compression spring 50 forces the pedestal 30 and attached rod 40 essentially vertically upward at a rapid, accelerated rate until the top spring retaining plate 44 engages the shoulder 68. The upward accelerated motion of the pedestal 30 projects the ball 32 upwardly in a generally vertical path to a suitable location within the strike zone of the batter, where the batter swings his bat at the ball in attempted coordination with his forward stride. With practice the stride and swing of the batter will become highly coordinated.

The maximum height of the trajectory of the ball 32may be varied whenever desiredby the location of collar 76 relative to threaded sleeve 72 to vary the at rest compression of the spring 50 between bearing plates 44 and 54.

Almost as the plunger 40 is released to so toss the ball 32, the pawl 126 will ride over the shoulder 108 as the pawl is forced upward along ramp 113, causing the pawl and bar 104 to again be disposed as illustrated in FIG. 10.

If desired, a replica of home plate 171 (shown in dotted lines in F l6. 8) may be attached to or placed adjacent the base 22 at the ball throwing mechanism 20. The plate 171 may be attached in any suitable way (not shown), such as by dowels laterally projecting from the plate 171 whichare received by blind bores in the base 22. The plate 171 is preferably interchangeably attachable to either side of the base 22 to accommodate use of the batting training apparatus by both right and left-hand batters. When a left-hand batter uses the apparatus, the plate 171 is attached to the base 22 on the edge directly opposite the position illustrated in FIG. 8. The lefthand batter will then depress the treadle with his right foot and stride off the treadle, his foot moving in a direction opposite that illustrated in dotted lines in FIG. 8.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is, therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come'within the meaning and range of equivalency of the claims are therefore to be embraced therein.

We claim:

1. In a baseball throwing apparatus for use in developing coordination between the stride and the swing of a batter, the apparatus comprising a base, a generally vertically erect plunger supported by the base and presenting a ball-receiving pedestal at the upper end ofthe erect plunger, said plunger being biased upwardly toward a vertically extended position, plunger latching structure carried by the base and selectively shiftable between one position holding the plunger and pedestal in a depressed loaded condition counter to the bias and an open position releasing the loaded plunger and pedestal to hurl the ball vertically into the air by force of said bias and a foot-receiving treadle which is releasably connected to the plunger latching structure to shift the plunger latching structure from the one position to the open position when the foot is lifted from the treadle as when the batter strides forward.

2. In a baseball throwing apparatus as defined in claim 1 wherein said bias is provided by a compression spring structure which is confined within a vertically disposed cylindrical casing which is anchored to the base, the casing presenting stop structure for defining the vertically extended position.

3. In an apparatus as defined in claim 1 further comprising selectively settable structure for varying the magnitude of the bias acting upon the vertically erect plunger to correspondingly vary the height to which the ball is tossed when the plunger latching structure is shifted by the treadle from the one position to be open position.

4. ln an apparatus as defined in claim 3 wherein said bias is provided by a compression spring structure concentrically surrounding at least part of the plunger and interposed between spaced bearing structure, onebearing structure being positioned by the selectively settable structure to vary the at rest length and the stored force within the compression spring structure in the vertically extended position for controlling the height to which the ball is tossed.

5. In an apparatus as defined in claim 1 wherein said plunger comprises an abutment surface and said plunger latching structure comprises (a) movable detent means biased to engage the abutment surface to hold the plunger and pedestal in the one position and (b) means-interposed between the detent means and the treadle which cause the detent to be displaced counter to the detent bias out of engagement with the abutment surface accommodating movement of the plunger and pedestal to the open position when the foot is lifted.

6. In an apparatus as defined in claim 5 wherein said treadle is urged by bias means generally opposite to the direction in which the detent is biased.

7. In an apparatus as defined in claim 5 wherein said detent is a plunger receiving plate comprising an aperture through which the lower end of the plunger passes in moving between the one and the open positions, the plate being spring biased so that the aperture is normally somewhat eccentric to the path of the plunger whereby when the plunger is depressed into the one position it will eccentrically strike the edge of the aperture in the plate displacing the plate counter to its spring bias and the plate will return to near its normal condition when the lower end of the plunger has passed through the aperture causing the edge of the aperture to become situated adjacent a reduced diameter portion of the plunger and the plate to engage a shoulder situated at the termination of the reduced diameter portion of the plunger to restrain the plunger and pedestal in the one position, the plate being associated with an elongated arm which is engaged and displaced along with the plate counter to the plate bias by the treadle when the foot is lifted disengaging the shoulder of the plunger and the plate thereby releasing the plunger and pedestal to the open position.

8. In an apparatus as defined in claim 7 wherein said treadle is spring biased away from the plate and comprises a pawl adapted to be displaced over a shoulder of the elongated arm when the treadle is depressed by the foot of the user counter to the treadle bias, the pawl engaging the shoulder of the elongated arm in surface-to-surface relation, the bias of the treadle displacing the elongated arm counter to the plate bias by reason on the pawl-shoulder engagement to cause the disengagement of the shoulder of the plunger and the plate to release the plunger and the pedestal to the open position when the foot is removed from the-treadle.

9. ln an apparatus as defined in claim 8 further comprising a ramp adapted to progressively separate the pawl and the pawl engaging shoulder as the elongated arm is displaced by the treadle bias counter to the plate bias after the foot is lifted so that as soon as the plunger and pedestal are released to the open position the pawl and the pawl receiving shoulder separate into spaced relation onefrom the other under the respective forces of the treadle bias and the spring bias.

10. In a method of tossing a ball into the air in an essentially vertical direction, the ball being carried upon a pedestal which is biased toward an elevated position and which carries a downwardly projecting shaft: forcing the ball-holding pedestal and shaft loaded vertically downward along a generally vertically disposed axis into a loaded position counter to the bias, laterally displacing locking structure in respect to the axis, locking the pedestal in the loaded position with the locking structure, releasably connecting a foot receiving treadle to the locking structure only after the pedestal has been locked in the loaded position by depressing a foot against the foot receiving treadle preparatory to unlocking the pedestal, and lifting the foot from the treadle to cause the pedestal and the shaft to be unlocked and to be vertically displaced upwardly along said axis from the loaded position to toss the ball from the pedestal into the air.

11. In a methodas defined in claim 10 wherein said forcing step is preceded by adjusting the force initially comprising the bias to thereby control the height to which the ball is tossed.

12. In a batting training apparatus for projecting a ball vertically into the air comprising vertically erect compression spring means, ball holding means having its longest axis in vertical alignment with the erect spring means and against which the upper end of the spring means abut, lower spring abutment means against which the lower end of the spring means abut, means for locking the spring means in a compressed loaded condition against inadvertent release and being selectively displaceable from one position locking the spring means in the compressed condition and an open position releasing the spring means, means for displacing the locking means to thereby toss the ball into the air and means for varying the relative positions of the ball holding means and the lower spring abutment means to alter the force stored in the erect spring means at any given time to thereby regulate the distance which the ball will be projected into the air,

13. ln an apparatus as defined in claim 12 further comprising cylindrical surrounding the compression spring means and limiting the upward movement of the ball holding means, wherein said lower spring abutment means comprise bearing means disposed within the cylindrical casing with projections extending through slots in the cylindrical casing and wherein the varying means comprise a collar threadedly engaged with the cylindrical casing and abutting against the projections counter to the force of the compression spring means whereby when the collar is threadedly displaced relative to the cylindrical casing the bearing means will follow the collar by reason of the abutment between the collar and the projections to change (a) the distance between the bearing means and the ball holding means and (b) the force stored within the compression spring means.

14. In an apparatus as defined in claim 12 further comprising vertically oriented guide means defining the path traversed by the compression spring means and the ball holding means when the compression spring means is moved to the loaded condition and when the compression spring means is released.

15. A batting trainer apparatus comprising:

a ball receiving pedestal attached to a vertically displaceable elongated plunger, the plunger having a tapered lower end and a reduced diameter portion and shoulder adjacent the trailing end;

a compression spring essentially concentric about the plunger and interposed in a partially compressed state between a lower bearing plate and an upper bearing plate, which upper bearing plate is fastened to the plunger adjacent the top end thereof and to the pedestal adjacent the lower end thereof to bias the plunger upwardly, the upper bearing plate, the spring and at least a portion of the plunger being enclosed by and vertically displaceable within a casing having a hollow cylindrical interior and presenting adjacent the uppermost end of the casing an inwardly directed radial shoulder which defines the uppermost position of the plunger, the upper bearing plate and the pedestal;

a generally vertical guide sleeve having a hollow bore with an inside diameter slightly larger than the outside diameter of the plunger and slidably receiving the plunger to maintain the plunger in a substantially vertical orientation during reciprocation;

a generally horizontally disposed base supporting the guide,

the casing, and the lower bearing plate in a relatively stationary state and also supporting the plunger and the plunger in a generally vertically extending state, during use; laterally displaceable plunger latching plate carried for such movement by the base at a location adjacent the guide sleeve, the plate presenting an aperture selectively positionable in and out of alignment with the bore of the guide sleeve transverse aperture, the latching plate being pivotally joined near one end to an elongated arm which has an upstanding shoulder adjacent the other end thereof, and biasing structure urging the latch plate and elongated arm to a position where the plate aperture is normally somewhat out of alignment with the bore of the guide sleeve to cause the plate adjacent the plate aperture to abut the shoulder of the plunger and restrain the plunger in a loaded position;

a foot operable treadle biased generally opposite the plate bias, the treadle being connected for reciprocable movement to the base and presenting a pawl adapted to rest in a first position upon the elongated arm out of contact with the upstanding shoulder and to engage the shoulder of the elongated arm when the treadle is depressed by the foot of the batter counter to its bias and the pawl is thereby forced into surface-to-surface contact with the shoulder of the elongated arm; and

a ramp situated adjacent the upstanding shoulder for engaging and guiding the pawl in an upward direction as the treadle, the pawl, the elongated arm and the plunger latching plate, under force ofthe treadle bias, move away from the plunger once the batter lifts his foot from the treadle until the plunger is released from the loaded position by such displacement of the plate and the plunger is axially displaced vertically upward by the force of the compression spring to vertically hurl the ball airborne following which the ramp will guide the pawl out of association with the upstanding shoulder of the elongated arm and the treadle and pawl under the treadle bias and the elongated arm and plate under the plate bias will be oppositely displaced a predetermined distance respectively.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N03 ,545 ,752 Dated December 8 1970 Inventor( Max ill et 3.1.

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 57, "aligned" should read of line 73 "present" should read presents Column 3, line 6, "92" should read 94 line 33, cancel "hereinafter mo: fully"; line 36, "see FIG. 1)" should read (see FIG. 1) Column 4, line 5, "rocket" should read rocker Colum1 5, line 58, "be" should read the Column 7, line 7, "cylindrical surrounding" should read a cylindrical casing surrounding Signed and sealed this 13th day of April 1971.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, J Attestlng Officer Commissioner of Patent 

